Method for manufacturing textile products having improved crease resistance



1970 TOHRU KITAZAWA ETAL 3, ,75

METHOD FOR MANUFACTURING TEXTILE PRODUCTS HAVING IMPROVED GREASE RESISTANCE Filed Aug. 13, 1968 IOO "/ FROM GIVEN EXTENSION TENSILE RECOVERY IN O IO 20 3O 4O 5O EXTENSION IN /0 7Q y b C o o Z d TENSILE RECOVERY IN O IO -50 7O 8O BLENDING RATIO OF SYNTHETIC FIBERS IN United States Patent 3,546,756 METHOD FOR MANUFACTURING TEXTILE PRODUCTS HAVING IMPROVED CREASE RESISTANCE Tohru Kitazawa and Kazutorno Ishizawa, Osaka-shi, and

Toshio Ohta, Takarazuka-slii, Japan, assignors to Kanegafuchi Boseki Kabushiki Kaisha, Tokyo, Japan, a company of Japan Filed Aug. 13, 1968, Ser. No. 752,208 Claims priority, application Japan, Aug. 17, 1967, 42/ 52,836 Int. Cl. D06c 7/00 US. Cl. 2876 10 Claims ABSTRACT OF THE DISCLOSURE A method is disclosed for manufacturing textile products containing polypivalolactone fibers from to 30% by weight and at least one kind of natural or regenerated fibers. The textile products are given an improved crease resistance by applying a wet thermal treatment at a temperature between 110 and 120 C. The product is subjected to the thermal treatment either in the form of spinning yarns or textile fabrics for the purpose of elasticization. Even in case of blending the polypivalolactone fiber at a relatively low blending ratio, products having an excellent elastic property can be obtained.

The present invention relates to a method for manufacturing textile products having improved crease resis tance, and more particularly relates to a method for manufacturing textile products having improved crease resistance from blended yarns containing from 5 to 30% by weight of polypivalolactone staple fibers by applying a thermal treatment upon the products while they are in a wet condition.

One of the conventional methods for manufacturing textile products provided with preferable resilience such as crease resistance, wash-and-wear property and heat-setting ability, comprises blending synthetic fibers such as polyester fibers, polyacrylonitrile fibers, polypropylene fibers, nylon fibers and vinylon fibers with natural fibers or regenerated fibers. However, in this type of manufacturing method, it has been generally required to blend such synthetic fibers at a blending ratio higher than 50% in order to obtain suflicient resilience of the textile products manufactured. As it is well known, such high degree of blending of synthetic fibers is liable to cause troubles in the manufacturing process and increase in production cost under todays situation of textile industry.

Another conventional textile product provided with preferable resilience could be manufactured by blending synthetic segment elastomers having a large elastic recovery, such as the so-called Spandex fibers, with natural fibers or regenerated fibers at a blending ratio from 30 to 40%. However, in spite of their large elastic recovery, such elastomer fibers are generally provided with a relatively small Youngs modulus and such relatively small Youngs modulus of the elastomer fibers tends to result in poor stiffness of the textile products manufactured therefrom. Moreover, it has been difiicult or almost impossible to obtain such elastomer fibers having a fineness less than 40 denier by the conventional method for manufacturing them commercially. Consequently, the application of the conventional elastomer fibers in actual production of textile products having sufficient resilience was not successful although it was possible to produce them on a laboratory scale.

A principal object of the present invention is to provide a method for manufacturing textile products having improved crease resistance.

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Another object of the present invention is to provide a method for manufacturing textile products having crease resistance similar to that of the conventional textile products containing more than 50% of the above-described synthetic fibers by blending polypivalolactone fibers into material fibers at a low blending ratio such as in a range between 5 and 30% A further object of the present invention is to provide a method for manufacturing textile products having improved resilience of polypivalolactone fiber together with excellent functional properties of natural fibers, such as good hygroscopic property of cotton fibers, luster of silk fibers, crispness of jute fibers, etc., contained in the product at a blending ratio higher than 70%.

A still further object of the present invention is to provide a method for manufacturing textile products having improved resilience at a relatively low production cost and relatively few troubles in the manufacturing process.

In accordance with the above-described objects, the method of the present invention comprises spinning blended yarns from material fibers containing from 5 to 30% by weight of polypivalolactone staple fibers and at least one of natural of regenerated fibers; forming a fabric having a configuration composed of a plurality of such blended yarns; and applying a thermal treatment upon the fabric thusly obtained at a temperature from to C. in a wet condition.

The term polypivalolactone as used herein refers to a linear polymeric material having the formula and obtained by condensation polymerization of hydroxypivalic acids, esters of hydroxypivalic acids or pivalolactones.

The term pivalolactone staple fibers as used her in refers to staple fibers manufactured by melt spinning filaments from polypivalolactones, polymeric mixtures mainly composed of polypivalolactones, copolymers mainly composed of pivaloloctones and/ or mixtures of the abovedescribed polymeric substances, drawing the filaments after spinning and cutting the drawn filaments into short fibers by any of the known cutting methods.

The term elasticized polypivalolactone staple fibers as used herein refers to polypivalolactone staple fibers which are elasticized by a method hereinafter described in details.

Further features and advantages of the present invention will be apparent from the ensuing description with reference to the accompanying drawings to which, however, the scope of the invention is in no way limited.

FIG. 1 is a graphical drawing showing the relations between percent elongation and the corresponding percent tensile recovery for various specimen fibers.

FIG. 2 is a graphical drawing showing the relations between percent blending ratio of blending fibers and the resulting percent crease recovery of the textile product Obtained.

Referring to FIG. 1, the relation between extension in percent and tensile recovery in percent from given extension is graphically shown for various kinds of material fibers. In the drawing, the curve designated with a corresponds to elasticized polypivalolactone fibers, the curve b to non-elasticized polypivalolactone fibers, the curve 0 to nylon 6 or nylon 66 fibers, the curve d to wool fibers, the curve 2 to polyester fibers, the curve 1 to acrylic fibers, the curve g to silk fibers and the curve I: to viscose rayon fibers.

One of the outstanding features of polypivalolactone fibers is that their elastic property can be remarkably enhanced by applying thermal treatment upon the polypivalolactone fibers at a temperature higher than 100 C. In other words, elasticization of polypivalolactone fibers takes place when they are thermally treated at a temperature higher than 100 C. This fact is clearly proved by the result shown in the drawing. In the drawing, the tensile recovery from 50% extension of nonelasticized polypivalolactone fibers is assumed to fall within a range between 20 and 50% while that of elasticized polypivalolactone fibers ranges between 80 and 99% That is to say, while the elastic property of non-elasticized polypivalolactone fibers is substantially similar to that of the other kinds of fibers, that of the polypivalolactone fibers can be remarkably enhanced by the application of an elasticizing thermal treatment.

7 Consequently, during a spinning process, blending of non-elasticized polypivalolactone fibers with other material fibers can be carried out without any trouble due to the similarity of elastic properties of both components, and it is possible to obtain spinning yarns by the ordinary spinning process. However, when the fabric manufactured by weaving, knitting or netting the above-described spinning yarns are subjected to a thermal treatment at a temperature higher than 100 C., elastic property potentially inherent in the non-elasticized polypivalolactone fibers is developed and a large crease resistance is bestowed on the textile products. In some cases, the above- 110 to 120 C., and preferably the heat treating is carried out in a heated fluid atmosphere as more fully explained below. Selection of the optimum heating temperature should be made in consideration of the heating time. A heating temperature lower than 110 C. requires a relatively long heating time, which is difficult to be adopted in the actual manufacturing process. On the contrary, when the heating temperature is higher than 120 C., such a high heating temperature is liable to cause deterioration of the qualities of the material fibers such as Wool or silk fibers and, as a result, the commercial value of the textile products obtained by the treatment becomes lower.

In the thermal treatment, it is further required to carry out the heating operation in a wet condition in order to obtain a uniform elasticizing effect at a relatively low heating temperature. In case elasticization of polypivalolactone fibers is carried out in the form of spinning yarns, the spinning yarns are subjected to the thermal treatment while in the form of a skein, a package or a successively running path, while in case elasticization of polypivalolactone fibers is carried in the form of woven, knitted or netted fabrics, the fabrics are subjected to the thermal treatment while in the form of a spreaded cloth, a folded cloth, a hanging cloth, a twisted cloth or a successively running path. Furthermore, both the spinning yarn and the textile products can be subjected to the thermal treatment either in a dimensionally restricted condition or in a dimensionally free condition.

In the following Table 1, elastic properties of a broad cloth composed of only polypivalolactone fibers before and after the elasticizing thermal treatment are illustrated together with those of a blended broad cloth composed of 15% by weight of polypivalolactone fibers and 85% by weight of cotton fibers for comparison.

TAB LE I Test specimen Broad cloth cori tgining polypivalolactone ers only Tensile recovery Gulleys Elastic Elongation from 50% Crease stifiness Tenacity in modulus at break extension recovery Measured elastic properties gJdenier in g./denier in percent in percent in percent Warp Filling Before elasticization 4-6 -30 20-100 35-60 60-70 8. 0 4. 0 After elasticization 4. 5-6. 5 -35 50-140 90-98 88-93 10. 3 5. 5

staple fibers should be selected in accordance with those of the other material fibers to be blended with polypivalolactone fibers. Too much difference in those configurational features between the components tends, as is wellknown by ones skilled in the art, to cause abnormal performance of the fibers during the spinning operation. In case polypivalolactone fibers are to be blended-with fibers having relatively short staple length such as cotton fibers, viscose rayon fibers or acetate fibers, it is preferable to carry out the blending in the mixing and blowing process at a given blending ratio. In case polypivalolactone fibers are to be blended with fibers having relatively long staple length such as wool fibers, silk fibers or jute fibers, it is preferable to carry out the blending by doubling slivers of individual component material fibers at a given blendmg ratio.

The blending ratio of polypivalolactone fibers ranges between 5 and more preferably between 15 and 30%. Little additional eifects on the elastic property of the textile products obtained can be expected by increasing the blending ratio over 30%, which results only in waste of money. On the contrary, suflicient crease resistance of the textile products obtained cannot be expected when the blending ratio is lower than 5%.

With respect to the thermal treatment required for development of the potential elastic property of the nonelasticized polypivalolactone fibers, the heating temperature plays the most important role. Usually, the thermal treatment should be carried out at a temperature from Indices of elastic property of the specimen cloth shown in the table are measured in the following methods.

(1) Elastic modulus (g./denier)In the load-elongation diagram of the specimen cloth, a straight line is drawn tangential to the load-elongation curve at the position close to the Zero loading point of the curve. On the elongation axis of the diagram, a point A is marked at a position L mm. from the starting point 0 of the curve. A straight line perpendicular to the elongation axis and which passes through point A is drawn, and the intersection of the straight line with the above-described tangential line is marked B. A straight line parallel to the elongation axis is drawn through point B and the intersection of the line with the load axis is marked C. Then the elastic modulus E is given by;

W-S E 2 US wherein:

L=U 1 in mm. W=OO in g.

S=Length of the specimen in mm.

d=Fineness of the fiber used for the specimen cloth in denier.

HS=Elongation rate in mm./ min.

CS=Travelling speed of the recording tape in min/min.

Crease recovery (percent) =fi 100 In order to obtain the average, measurements were repeated times in the warp and filling directions.

(3) Stiffness-stillness of the specimen is measured with a Gulleys stiffness tester.

The following examples are illustrative of the present invention but are not to be construed as limiting the same.

EXAMPLE 1 Two samples of polypivalolactone/ cotton blended spinning yarns were prepared in the manner shown in Table 2.

TABLE 2 Sample Nos.

Fineness and staple length of polypivalolactone fibers. Blending ratio of polypivalolactone fibers 30% Blending ratio of cotton fibers 70% 80% Count of the yarn in English system 's 30's Number of twists in turns/inch 21. 5 21. 5

1 1.5 denier x 34 mm.

The sample yarns thus prepared were subjected to a thermal treatment by placing them in a heated fluid atmosphere of hot water at 120 C. for 30 minutes in the form of packages in an autoclave, and the yarns thus elasticized were Woven into a plain weave cloth having warp density of 72 ends/inch and filling density of 69 picks/inch. For the purpose of comparison, two sample cloths Nos. 3 and 4 also having the above-described construction were woven from blended yarns composed of 65% by weight of polyester fibers and 35% by weight of cotton fibers, and 30% by weight of polyester fibers and 70% by weight of cotton fibers, respectively. The resulting crease recovery of the samples are illustrated in Table 3 and FIG. 2.

In FIG. 2, the curve designated with a corresponds to warp crease recovery of samples Nos. 1 and 2, the curve b to filling crease recovery of samples Nos. 1 and 2, the curve 0 to warp crease recovery of samples Nos. 3 and 4 and the curve d to filling crease recovery of samples Nos. 3 and 4, respectively.

As is clearly understood from the results shown in the table and the drawing, the crease recovery of cloths made of blended yarns containing from 20 to 30% by weight of polypivalolactone fibers, that is samples Nos. 1 and 2, is similar or larger than that of cloths made of blended yarns containing from to by weight of polyester fibers, that is samples Nos. 3 and 4.

EXAMPLE 2 Two samples of polypivalolactone/ silk blended spinning yarns were prepared in the manner shown in Table 4.

TABLE 4 Sample Nos.

FilgllSS and staple length of polypivalolactone ers. Blending ratio of polypivalolactone fibers 2 20% 30% Blending ratio of silk fibers 70% Count of the yarn in English system 140s/2 1405/2 Number of twists in turns/inch:

Primary 19 19 Secondary 16. 2 16. 2

1 15 denier X 76-12.! cm. 2 Blended in the form of slivers in the drawing process.

The sample yarns thus prepared were subjected to a thermal treatment by placing them in a heated fluid atmosphere in a high pressure steamer at C. for 45 minutes, and the yarns thus elasticized were woven into a plain weave cloth having warp desnity of 115 ends/ inch and filling density of 89 picks/ inch. For the purpose of comparison, a sample cloth No. 7 also having the above-described construction were woven from yarns composed of 100% silk fibers. The resulting crease recovery and stillness of the samples are illustrated in Table 5.

TABLE 5 Sample Nos.

As is clearly shown in the above table, sample cloths made of blended yarns containing polypivalolactone fibers are provided with superior elastic property to that made of silk fibers only.

EXAMPLE 3 An woven cloth made of polypivalolactone/wool blended yarn was prepared in a manner shown in Table 6.

TABLE 6 Sample No. 8:

Fineness and staple length of polypivalolactone sliver 3 denier X6.476 cm. Blending ratio of polypivalolactone fibens 20% Blending ratio of wool fibers80% "Count of the yarn in English system46=s/2 Number of twists in turns/ meter Prim ary530 Secondary560 Design of the cloth woven mat of plain weave Yarn density per 1 inch Warp-82 Filling75 Weight in g./m."=447 1 Blended in the form of slivers in the drawing process.

The sample cloth thus prepared was subjected to a thermal treatment by placing them in a heated fluid atmosphere in a high pressure streamer at C. for 15 minutes. For the purpose of comparison, a woven mat of plain weave (Sample No. 9) made of blended yarns 46s/2 composed of 50% by weight of polyester fibers and 50% by weight of wool fibers and a woven mat of plain weave (Sample No. 10) made of 100% wool yarns of 46s/2 were prepared in the same manner as in Sample 8 with the exception of the thermal treatment.

The resulting crease recovery of the sample cloths is illustrated in Table 7, wherein it is apparent that the polypivalolactone blended cloth, that is sample 8, is provided with a larger crease recovery than those of other cloths containing no polypivalolactone fibers.

TABLE 7 Sample Nos.

Crease recovery in percent:

Warp c 85.3 84.4 79.1 Filling 88.0 86. 0 81.0

EXAMPLE 4 A woven cloth made of polypivalolactone/ viscose rayon blended yarns and a woven cloth made of 100% viscose rayon yarns were prepared in the manner shown in Table 8.

After the desizing operation, both sample cloths were subjected to a thermal treatment in a high pressure jigger at 115 C. for min. and the resulting crease recovery of both sample cloths are illustrated in Table 9, wherein it is apparent that the crease recovery of the cloth containing polypivalolactone fibers is far superior to that of the cloth which does not contain them.

TABLE 9 Sample Nos.

Crease recovery in percent:

ar 65. 2 52. 3 Filling 68. 4 53.5

While the invention has been described in conjunction with certain embodiments thereof, it is to be understood that various modifications and changes may be made without departing from the spirit and scope of the invention.

What is claimed is:

1. A method of manufacturing crease-resistant blended yarn comprising: providing a blended yarn composed of polypivalolactone staple fibers and wool fibers; and heat treating said blended yarn in a wet condition at a temperature between ll0120 C. to efiectively elasticize said polypivalolactone staple fibers; whereby crease resistance is imparted to said blended yarn without thermally damaging said wool fibers.

2. A method according to claim 1 wherein said heat treating step comprises placing said blended yarn in a heated fluid atmosphere.

3. A method according to claim 1 wherein said providing step comprises providing a blended yarn having groin 5 to 30% by weight of polypivalolactone staple bers.

4. A method of manufacturing crease-resistant blended yarn comprising: providing a blended yarn composed of polypivalolactone staple fibers and silk fibers; and heat treating said blended yarn in a wet condition at a temperature between -l20 C. to effectively elasticize said polypivalolactone staple fibers; whereby crease resistance is imparted to said blended yarn without thermally damaging said silk fibers.

5. A method according to claim 4 wherein said heat treating step comprises placing said blended yarn in a heated fluid atmosphere.

6. A method according to claim 4 wherein said providing step comprises providing a blended yarn having from 5 to 30% by weight of polypivalolactone staple fibers.

7. A method of manufacturing crease-resistant blended yarn fabric comprising: providing a blended yarn composed of polypivalolactone staple fibers and wool fibers; forming said blended yarn into a fabric; and heat treating said fabric in a wet condition'at a temperature between 110l20 C. to elasticize said polypivalolactone staple fibers; whereby crease resistance is imparted to said blended yarn fabric without thermally damaging said Wool fibers.

8. A method according to claim 7 wherein said providing step comprises providing a blended yarn having from 5 to 30% by weight of polypivalolactone staple fibers.

9. A method of manufacturing crease-resistant blended yarn fabric comprising: providing a blended yarn composed of polypivalolactone staple fibers and silk fibers; forming said blended yarn into a fabric; and heat treating said fabric in a wet condition at a temperature between 110-120 C. to elasticize said polypivalolactone staple fibers; whereby crease resistance is imparted to said blended yarn fabric without thermally damaging said silk fibers.

10. A method according to claim 9 wherein said providing step comprises providing a blended yarn having from 5 to 30% by weight of polypivalolactone staple fibers.

References Cited UNITED STATES PATENTS 3,299,171 1/1967 Knobloch et a1 260857 3,345,343 10/1967 Tietz 260-78.3 3,379,001 4/1968 Campbell et al. 57140(B) LOUIS K. RIMRODT, Primary Examiner 

